Tank possibility for Mercatoris

[bronco300]

well this is the setup I'm CONSIDERING right now...I have available to be a 40gallon breeder and 20gallon long. And I know the 40 breeder may be a larger system for such tiny little guys...but I was hoping to have a really nice aquascaped tank, and be able to do just enough rock/barnacles to have a more open area as well so its not all crowded in there or anything,...and be able to make the 20long a sump and put a lot of rock down in there to help with filtration,etc.

In the picture you can see my layout for equipment wise....and on the lighting, not sure if anyone has tried it....but I wondered about have a red lamp on the far left, an actinic in the middle, and daylight on the far right. Being in a 40, the picture is obviously not to scale, and itd probably not be a very big fixture/lamp....but I was thinking this way it would possibly give the octopus the effect of having a dark side where it would seem like they would be deeper or in a cave...then as they ventured right it'd be as if going out and about normally in a day....any thoughts?

Then of course not shown in the picture is sealing in everything to make sure the octos do not get into the sump, or if they do, that they don't get into the return pump.

Any suggestions, comments, ideas, hatred?

 

[DWhatley]

That is a big tank for a merc but if you can position some dens that they will accept, you might see them. I would consider 3 (possible 4-5 but I have only kept 3 adults together in this sized tank and if you are limiting the LR, then I would not exceed 3).

I don't think the lighting will be beneficial for the mercs and might limit your viewing. Mercatoris are fully nocturnal and just don't come out during the day. If your daylight lighting is off then it will be the darkest part of the aquarium and likely to be where they hide and hunt at night. I would recommend using a full tank red light and leaving it on all night (optional during the day, I leave mine on 24/7) and turning off the any other lighting a couple of hours before you hope to see them (in addition to the room lights). Mine have acclimated to this and it allows for active time viewing.

The best denning I have found for the mercs is to provide the giant purple barnacles about midway up the water column. The barnacles can be surrounded with LR so that it appears to be more of a hole than a shell. I place them so you can look in but so the light is not shinning directly into the den. Females seem to find these particularly attractive where my males have only used them on occassion (and have moved from den to den through out their lives).

 

[bronco300]

Awesome, thanks for the suggestions...is there really a point to the daylight lights then if it could possibly hinder their sight in the long run? Or would it still be important to give them that cycle of night and dad like normal?

I'm on the hunt for the barnacles, I'm pretty excited about them...I just wish I had a relative in California I could coax to get me some nice ones and pay for shipping...has anyone found a good source for some that won't break the bank too? Working at a fish stoer I have some perks, but this hasn't been one yet unfortunately.

 

[DWhatley]

You will want daylight lighting if you plan to have any kind of polyp, soft coral or macro algae but it should be on a timer so that evening falls at the same time. Mine have tended to come out (Sleazy does not leave her den but comes to the front) about 2 hours after the room is dark. Because Sleazy does not leave her den (and because each octopus has a little different personality), Neal can get her to eat around 6:00 even though the lights are on in the room (there is only a red light over the tank). Note that this is the first merc we have had that would eat this early. My most interactive merc (Sisturus) would actively look for food promptly at 11:00 but my others have not been as dependable to find. MIA (Missing In Aquarium) would disappear for a week or more at at time.

At one time the purple barnacles were very reasonable, I don't know why they have gotten so expensive. They are not harvested live (I have yet to find anyone who has even seen a live one (I think they are officially called pectens). There is an artificial one made but I don't know how well they would be received as a den. The best place to find them is in a shell or traveller's souvenier store but this generally applies to the coast. What you don't want is to buy some that have been coated with a varnish. If you work for a chain fish store, try some of the independents.

 

[bronco300]

I dont really think I intend on doing any corals...I have another tank already with corals...and I've kind strayed away so I dont spend quite as much on all the corals I seem come in to our shop Which is not a large chain or anything...its premium aquatics(.com) if anyone has ever heard of it.

But anyways, if I did any, I thought I'd maybe go with some sort of grasses actually, or just corals that don't need light if I dont want to use any.

Have you been able to tell with, or anyone for that matter...I know these are nocturnal, but are they extremely sensitive to ALL lighting, meaning that even a small lamp turned on in a 15x15 room on the opposite side they'd be able to tell and not come out because of that?

 

[DWhatley]

I have no pat answer on ambient light. I do think leaving the red light on 24/7 has helped mine to adjust (in a darkened room, the light is pretty bright and makes the tank very easy to observe but does not serve for photography). A lot will depend on the individual animal as well. Sleazy tollerates way more light than any of the others I have had.